Ch9 Neuromuscular Effects of Anesthetic Agents

Question 1

What are the neuromuscular effects of inhaled anesthetics?

Answer 1

Inhaled anesthetics can produce muscle relaxation during surgical procedures through central nervous system effects and direct action on the neuromuscular junction.

Question 2

Which potent inhaled agents are known for inducing muscle relaxation?

Answer 2

• Isoflurane
• Sevoflurane

Question 3

Does nitrous oxide contribute to muscle relaxation?

Answer 3

No, nitrous oxide does not cause muscle relaxation; only potent inhaled anesthetics do.

Question 4

How does increasing anesthetic doses affect muscle relaxation?

Answer 4

Increasing anesthetic doses enhances muscle relaxation.

Question 5

What is the impact of patient age on neuromuscular blockade?

Answer 5

Children require higher doses of neuromuscular blocking drugs due to higher plasma cholinesterase levels.

Question 6

What is the importance of maintaining one twitch during anesthesia?

Answer 6

Maintaining one twitch is crucial for recovery from paralysis and reducing post-operative complications.

Question 7

What drugs are discussed for achieving muscle relaxation without neuromuscular blockers?

Answer 7

• Propofol
• Fentanyl

Question 8

What is the role of anesthetic concentration in neuromuscular blockade?

Answer 8

Higher anesthetic concentrations require lower infusion rates of neuromuscular-blocking drugs.

Question 9

What is the significance of using less soluble inhaled agents for patients with myasthenia gravis?

Answer 9

Less soluble inhaled agents can avoid prolonged neuromuscular blockade.

Question 10

What preparatory measures should be taken for a patient susceptible to malignant hyperthermia?

Answer 10

• Flush the anesthesia machine
• Remove vaporizers
• Replace soda lime
• Initiate high-flow oxygen ventilation

Question 11

True or False: Inhalational agents like halothane can trigger malignant hyperthermia.

Answer 11

True

Question 12

What enhances the effect of neuromuscular blocking drugs during anesthesia?

Answer 12

Potent inhaled anesthetics enhance the effect of neuromuscular blocking drugs, reducing the need for higher doses.

Question 13

How can turning down anesthetic concentration affect muscle relaxants?

Answer 13

Turning down anesthetic concentration can reverse the effect of muscle relaxants, enhancing safety during anesthesia recovery.

Question 14

Fill in the blank: Higher plasma _______ levels in children require more vecuronium.

Answer 14

cholinesterase

Question 15

What should be avoided in patients susceptible to malignant hyperthermia?

Answer 15

Avoid using succinylcholine and volatile anesthetics.

Question 16

What is the benefit of maintaining a low dose of vecuronium with high concentrations of desflurane?

Answer 16

It achieves significant muscle relaxation while enhancing patient safety.

Question 17

What is the clinical importance of the neuromuscular effects of inhaled anesthetics?

Answer 17

They are crucial for managing conditions like myasthenia gravis and malignant hyperthermia.

Question 18

What happens to the train of four after eliminating the death strain?

Answer 18

There is an increase in the train of four, with increased Twitch height on all four twitches.

This indicates a recovery of neuromuscular function despite continuous Vecuronium infusion.

Question 19

What effect does the elimination of death strain have on tetany response?

Answer 19

There is an increase in tetany response, although some fade is still observed.

This demonstrates improvement in neuromuscular function over time.

Question 20

What are the implications of potent inhaled anesthetics on surgical demand for muscle relaxation?

Answer 20

They decrease the need for reversal and reduce the potential for postoperative nausea and vomiting.

This is particularly beneficial for patients with renal or hepatic failure.

Question 21

How does myasthenia gravis affect neuromuscular blocking during anesthesia?

Answer 21

Lower than normal doses of neuromuscular blockers are required, and titration to effect is necessary.

This is crucial to avoid excessive neuromuscular blockade.

Question 22

What is malignant hyperthermia?

Answer 22

A hereditary disorder characterized by a hypermetabolic state and a defect in the ryanodine receptor leading to increased calcium.

This condition can be triggered by certain inhalational anesthetics.

Question 23

Which inhalational agent is most concerning for triggering malignant hyperthermia?

Answer 23

Halothane is the most concerning inhalational agent for malignant hyperthermia.

It has a shorter median time to onset of symptoms compared to isoflurane and desflurane.

Question 24

What precautions should be taken when dealing with a patient suspected of being predisposed to malignant hyperthermia?

Answer 24

Avoid using succinylcholine and remove vaporizers from the anesthesia machine.

High flow oxygen should be used to flush the system.

Question 25

What is the effect of inhaled anesthetics on neuromuscular function?

Answer 25

Inhaled anesthetics enhance the effects of muscle relaxants and can cause relaxation by themselves. ## Footnote This has significant clinical implications in anesthesia administration.

Question 26

What is the recommended approach for anesthetizing a patient with myasthenia gravis?

Answer 26

Induce anesthesia as usual, then use a neuromuscular blocker titrated to effect, or use a potent inhalational agent alone. ## Footnote This minimizes the risk of excessive neuromuscular blockade.

Question 27

True or False: All inhalational agents are equally effective in triggering malignant hyperthermia.

Answer 27

False. ## Footnote Some inhalational agents are more likely to trigger malignant hyperthermia than others.

Question 28

Fill in the blank: The _______ receptor is defective in malignant hyperthermia.

Answer 28

ryanodine